AIM:To evaluate the surgical outcomes of the perfluorocarbon liquid(PFCL)-assisted inverted multilayer internal limiting membrane(ILM)flaps covering technique in macular hole retinal detachment(MHRD)in high myopia wit...AIM:To evaluate the surgical outcomes of the perfluorocarbon liquid(PFCL)-assisted inverted multilayer internal limiting membrane(ILM)flaps covering technique in macular hole retinal detachment(MHRD)in high myopia with axial length(AL)≥30 mm.METHODS:In this retrospective,interventional,consecutive comparative study,44 MHRD eyes were divided into two groups:the PFCL-assisted inverted multilayer ILM flaps covering technique group(Group 1,21 eyes)and the ILM peeling group(Group 2,23 eyes).The follow-up period was>12mo.Postoperative outcomes,including retinal reattachment,macular hole(MH)closure,and bestcorrected visual acuity(BCVA),were assessed.Statistical analysis using the Mann–Whitney U test and Fisher’s exact test was conducted to compare differences between groups.RESULTS:There were no statistically significant differences in baseline preoperative clinical characteristics,including age,sex,AL,diopters,duration of symptom,lens status,posterior staphyloma presence and extent of RD.Retinal reattachment rates were higher in Group 1(90.5%)than in Group 2(82.6%),without statistical significance(P=0.667).MH closure rates were significantly higher in Group 1(85.7%)than in Group 2(17.4%;P<0.001).The Group-1 BCVA(logMAR)improved significantly from 2.13±0.91 preoperatively to 1.21±0.66 postoperatively(P=0.026).The Group 2 BCVA improved significantly from 1.91±0.53 preoperatively to 1.19±0.41 postoperatively(P=0.032).However,there were no significant differences in visual-acuity improvement between groups(P=0.460).CONCLUSION:This technique offers a more effective approach for improving MH closure rates and postoperative visual function in MHRD with AL≥30 mm in high myopia.展开更多
The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel aircraft.In this study,a new way of nonlin...The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel aircraft.In this study,a new way of nonlinear flow control by interaction between two flexible flaps is proposed,and their flow control mechanism is studied employing the self-constructed immersed boundary-lattice Boltzmann-finite element method(IB-LB-FEM).The effects of the difference in material properties and flap length between the two flexible flaps on the nonlinear flow control of the airfoil are discussed.It is suggested that the relationship between the deformation of the two flexible flaps and the evolution of the vortex under the fluid-structure interaction(FSI).It is shown that the upstream flexible flap plays a key role in the flow control of the two flexible flaps.The FSI effect of the upstream flexible flap will change the unsteady flow behind it and affect the deformation of the downstream flexible flap.Two flexible flaps with different material properties and different lengths will change their own FSI characteristics by the induced vortex,effectively suppressing the flow separation on the airfoil’s upper surface.The interaction of two flexible flaps plays an extremely important role in improving the autonomy and adjustability of flow control.The numerical results will provide a theoretical basis and technical guidance for the development and application of a new flap passive control technology.展开更多
Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to ...Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to harvest and sacrifice the deep major artery. These flaps are supplied by a perforating artery issued from the deep peroneal artery or the posterior tibial artery, and the chainlinked adipofascial neurovascular axis around the sural/saphenous nerve. It is a versatile and reliable technique for soft-tissue reconstruction of the heel and ankle region with 180-degrees rotation. In this paper, we present its developing history, vascular basis, surgical techniques including flap design and elevation, flap variations in pedicle and component, surgical indications, and illustrative case reports with different perforating vessels as pivot points for foot and ankle coverage.展开更多
BACKGROUND： Major complications after pancreaticoduo- denectomy are usually caused by a leaking pancreaticojejunal anastomosis. Omental flaps around various anastomoses were used to prevent the formation of fistula.
Objective The objective of this report was to demonstrate the clinical application of free flow-through anterolateral thigh flaps for the treatment of high-tension electrical wrist burns.Methods We collected the data ...Objective The objective of this report was to demonstrate the clinical application of free flow-through anterolateral thigh flaps for the treatment of high-tension electrical wrist burns.Methods We collected the data of 8 patients with high-tension electrical wrist burns admitted to Beijing Jishuitan Hospital from January 2014 to December 2018.The clinical and pathological data were extracted from electronic hospital medical records.We obtained follow-up information through clinic visits.Results The injury sites for all 8 patients were the wrists,specifically 5 right and 3 left wrists,all of which were on the flexor side.Five patients had ulnar artery embolism necrosis and patency,with injury to the radial artery.Two patients had ulnar and radial arterial embolization and necrosis.The last patient had ulnar arterial embolization and necrosis with a normal radial artery.After debridement,the wound area ranged from 12 cm×9 cm to 25 cm×16 cm.The diagnoses for the eight patients were type II to type III high-tension electrical wrist burns.Free flow-through anterolateral thigh flaps(combined with great saphenous vein transplantation if necessary)were used to repair the wounds.The prognosis for all patients was good after six months to one year of follow-up.Conclusion Treating wrist types II and III high-tension electrical burns is still challenging in clinical practice.The use of free flow-through anterolateral thigh flaps(combined with great saphenous vein transplantation if necessary)to repair the wound and to restore the blood supply for the hand at the same time is a good choice for treating severe wrist electrical burns.展开更多
There is long-standing debate about sensate versus non-sensate free microvascular flaps among microsurgeons. The principle of connecting not only the vascular supply, but also sensitive nerves, in free tissue transfer...There is long-standing debate about sensate versus non-sensate free microvascular flaps among microsurgeons. The principle of connecting not only the vascular supply, but also sensitive nerves, in free tissue transfer is attractive. However, increased operating time and partial spontaneous innervation led to the common decision to restrict microsurgical tissue transfer to the vascular anastomosis and to leave the nerves ＂untreated＂. Nevertheless, in special cases such as breast reconstruction or extremity reconstruction, the question about sensory nerve coaptation of the flaps remains open. We present our experience with free microvascular tissue transfer for breast and extremity reconstruction and compare the data with previous literature and conclude that most free flap surgeries do not benefit from nerve coaptation.展开更多
Abstract Morphing wing structures are widely considered among the most promising technologies for the improvement of aerodynamic performances in large civil aircraft.The controlled adaptation of the wing shape to exte...Abstract Morphing wing structures are widely considered among the most promising technologies for the improvement of aerodynamic performances in large civil aircraft.The controlled adaptation of the wing shape to external operative conditions naturally enables the maximization of aircraft aerodynamic efficiency,with positive fallouts on the amount of fuel burned and pollutant emissions.The benefits brought by morphing wings at aircraft level are accompanied by the criticalities of the enabling technologies,mainly involving weight penalties,overconsumption of electrical power,and safety issues.The attempt to solve such criticalities passes through the development of novel design approaches,ensuring the consolidation of reliable structural solutions that are adequately mature for certification and in-flight operations.In this work,the development phases of a multimodal camber morphing wing flap,tailored for large civil aircraft applications,are outlined with specific reference to the activities addressed by the author in the framework of the Clean Sky program.The flap is morphed according to target shapes depending on aircraft flight conditions and defined to enhance high-lift performances during takeoff and landing,as well as wing aerodynamic efficiency during cruise.An innovative system based on finger-like robotic ribs driven by electromechanical actuators is proposed as morphing-enabling technology;the maturation process of the device is then traced from the proof of concept to the consolidation of a true-scale demonstrator for pre-flight ground validation tests.A step-by-step approach involving the design and testing of intermediate demonstrators is then carried out to show the compliance of the adaptive system with industrial standards and safety requirements.The technical issues encountered during the development of each intermediate demonstrator are critically analyzed,and justifications are provided for all the adopted engineering solutions.Finally,the layout of the true-scale demonstrator is presented,with emphasis on the architectural strengths,enabling the forthcoming validation in real operative conditions.展开更多
Mesenchymal stem cells(MSCs), multipotential cells that reside within the bone marrow, can be induced to differentiate into various cells, such as osteoblasts, adipocytes, chondrocytes, vascular endothelial progenitor...Mesenchymal stem cells(MSCs), multipotential cells that reside within the bone marrow, can be induced to differentiate into various cells, such as osteoblasts, adipocytes, chondrocytes, vascular endothelial progenitor cells, and other cell types. MSCs are being widely studied as potential cell therapy agents due to their angiogenic properties, which have been well established by in vitro and in vivo researches. Within this context, MSCs therapy appears to hold substantial promise, particularly in the treatment of conditions involving skin grafts, pedicle flaps, as well as free flaps described in literatures. The purpose of this review is to report the new advances and mechanisms underlying MSCs therapy against skin flaps necrosis.展开更多
Gurney Flaps(GFs) are used for improving the performance of variable speed tail rotors. A validated analytical helicopter model able to predict the main and tail rotor power is utilized. The fixed height GF has substa...Gurney Flaps(GFs) are used for improving the performance of variable speed tail rotors. A validated analytical helicopter model able to predict the main and tail rotor power is utilized. The fixed height GF has substantially small influence on the tail rotor power in hover and low to medium speed forward flight, and can obtain significant power reduction in high speed flight.This ability can be enhanced by decreasing the tail rotor speed. With the deployment of GF, the collective pitch of the tail rotor decreases, and the maximum tail rotor thrust increases. The GF can compensate the reduction of the maximum thrust by the decrease in the tail rotor speed. The GF with a height of 5% of the chord length can almost remedy 50% of the thrust reduction introduced by decreasing 10% of the tail rotor speed. With the increase of GF height, the maximum thrust generated by the tail rotor increases. The GF with larger height can cause the increase in the tail rotor power in hover and low to medium speed flight. The retractable GF can obtain more power savings than the fixed height GF. However, the benefit is substantially small even in high speed flight. Considering the side effects introduced by the active GF, the fixed height GF may be more preferable. The mechanism for the retractable GF to generate more tail rotor thrust is to increase the lift in advancing side due to the higher dynamic pressure.展开更多
· AIM: To reconstruct the extensive full-thickness defects of eyelids is a challenge for the plastic surgeon because of their complex anatomy and special functions.This article presents and discusses an improved ...· AIM: To reconstruct the extensive full-thickness defects of eyelids is a challenge for the plastic surgeon because of their complex anatomy and special functions.This article presents and discusses an improved surgical technique in which the orbicularis oculi myocutaneous flap is rotated through a "subcutaneous tunnel" in conjunction with a palatal mucosal graft employed for lining.·METHODS: Data from 22 eyes with extensive full-thickness eyelid defects from various causes between2009 and 2013 were analyzed in this study. After the different layers of eyelid were separated completely, a temporally based orbicularis oculi myocutaneous flap was designed following fishtail lines and was mobilized,leaving the base of the pedicle intact with a submuscular tissue attachment. The flap was then rotated through a "subcutaneous tunnel" to the defect, and the donor site was closed primarily. Posterior lamellar reconstruction was performed with a mucosal graft harvested from the hard palate.·RESULTS: All the flaps were survived without any healing problems. There was no corneal irritation, flap contraction, or significant donor-site morbidity in the follow-up period. The incision scars were almost invisible.The defects were repaired completely, and the evaluations showed satisfactory function and appearance.·CONCLUSION: This technique is an improved singlestage operation and can be applied to repair large, full-thickness eyelid defects from various causes. With our method, the functional and aesthetic results can be obtained in either the upper or lower eyelids.展开更多
·AIM: To provide superior cosmetic results and reduce complications, unlike traditional evisceration coupled with implant insertion technique and its modifications,we have developed a novel and simple technique f...·AIM: To provide superior cosmetic results and reduce complications, unlike traditional evisceration coupled with implant insertion technique and its modifications,we have developed a novel and simple technique for anophthalmic patients.·METHODS: All patients who underwent the scleral-muscle flaps procedure in evisceration with the placement of hydroxyapatite implant were included in the study. Main outcome measures were complications such as exposure, infection, chemosis, conjunctival inclusion cysts, granulomas. Meanwhile, implant motility was indirectly measured and the results were collected and analyzed.· RESULTS: A total of twenty-eight patients were enrolled in the study. Eighteen were men(64.29%) and ten were women(35.71%). Ages ranged from 18 to 65y(mean age, 32 years old). Mean follow-up was 12.32mo(range, 9-16mo). All patients received a hydroxyapatite implant. The average diameter of the implant was 19.29 ±1.36 mm(range, 18-22 mm). Minor complications occurred in 3 patients, and a major complication was observed in 1 patient. Mean motility were 11.04 ±1.45 mm horizontally(range, 7-14 mm) and 8.57 ±1.50 mm vertically(range, 5-12 mm).·CONCLUSION: The sclera-muscle flaps technique in evisceration with hydroxyapatite implantation is simple and practical that eases the surgical procedure, enables a proper size hydroxyapatite implantation, distinctively reduces complications and provides superior surgery results, especially the motility of the implant.展开更多
The effect of Gurney flaps with different heights on the S809 airfoil and NH1500 blade is numerically simulated.The influence of the Gurney flap is analyzed at different wind speeds and the comparison of the aerodynam...The effect of Gurney flaps with different heights on the S809 airfoil and NH1500 blade is numerically simulated.The influence of the Gurney flap is analyzed at different wind speeds and the comparison of the aerodynamic performance is given between the blades with and without the Gurney flap.The results demonstrate that a Gurney flap added on the blade can greatly increase the efficiency of the wind turbine especially at high wind speeds.展开更多
Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January ...Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January 2009 and December 2013, 19 patients with DSWI after median sternotomy for cardiac surgery were admitted to our hospital, including 14 males(73.7%) and 5 females(26.3%), aged 55±13(18-78) years. According to the Pairolero classification of infected median sternotomies, 3(15.8%) patients were type II, and the other 16(84.2%) were type III. Surgical procedure consisted of adequate debridement of infected sternum, costal cartilage, granulation, steel wires, suture residues and other foreign substances. Sternal reconstruction used the bilateral pectoralis major or plus rectus abdominis muscle flaps to obliterate dead space. The drainage tubes were placed and connected to a negative pressure generator for adequate drainage. Results There were no intraoperative deaths. In 15 patients(78.9%), bilateral pectoral muscle flaps were mobilized sufficiently to cover and stabilize the defect created by wound debridement. 4 patients(21.0%) needed bilateral pectoral muscle flaps plus rectus abdominis muscle flaps because their pectoralis major muscle flaps could not reach the lowest portion of the wound. 2 patients(10.5%) presented with subcutaneous infection, and 3 patients(15.8%) had hematoma. They recovered following local debridement and medication. 17 patients(89.5%) were examined at follow-up 12 months later, all healed and having stable sternum. No patients showed infection recurrence during the follow-up period over 12 months. Conclusion DSWI following median sternotomy may be effectively managed with adequate debridement of infected tissues and reconstruction with bilateral pectoralis major muscle or plus rectus abdominis muscle flap transposition.展开更多
BACKGROUND In daily life and work,there are more and more patients with trauma to the hand,which often results in skin and soft tissue defects.Although there are many repair methods,the function and appearance of the ...BACKGROUND In daily life and work,there are more and more patients with trauma to the hand,which often results in skin and soft tissue defects.Although there are many repair methods,the function and appearance of the fingers will be adversely affected if the repair is inadequate.CASE SUMMARY In the present report we describe an 18-year-old male patient whose right hand was mangled by a machine.X-ray imaging showed that a right hand bone(middle finger)was absent and the alignment was poor.After hospitalization,he was diagnosed with a severe right hand injury,skin and soft tissue defects,partial finger defects,and a skin degloving injury.He underwent reconstructive surgery with anterolateral thigh and ilioinguinal flaps.After two repair operations,satisfactory results were obtained,including good fracture healing,good skin flap shape,and good wrist joint function.CONCLUSION This case highlights the good effect of anterolateral thigh and ilioinguinal flaps repair technique on severe palm injury.展开更多
Objective： To study the possibility of using portions of deepithelialized myocutaneous flaps to the reconstruction of thoracic tracheal defects after resection of a large tumor. Methods： From June 2007 to June 2012,...Objective： To study the possibility of using portions of deepithelialized myocutaneous flaps to the reconstruction of thoracic tracheal defects after resection of a large tumor. Methods： From June 2007 to June 2012, five cases of defects of the thoracic trachea were reconstructed by applying portions of deepithelialized myocutaneous flaps. The patients were 27-61 years old with 4 male cases and 1 female. The cervical trachea ranged in diameter from 4-8.5 cm with circumferences of approximately 1/3-2/5 of the bronchial circumference. Results： M1 five patients with thoracic tracheal defects after resection of a large tumor were cured of portions of deepithelialized myocutaneous flaps, with no tracheal stricture remaining and vomica successfully eliminated. During the first 1 to 3 months after the operation, bronchoscopy showed that the tracheal lumens were smooth, and the visible skin of the musculocutaneous flaps became gray and exhibited a small amount of white discharge. Conclusions： Despite this being a small series and short follow-up, this thoracic tracheal reconstruction with portions of deepithelialized myocutaneous flaps shows encouraging preliminary results and could be an alternative to other methods for the treatment of carefully selected patients with thoracic tracheal defects.展开更多
The seamless trailing edge morphing flap is investigated using a high-fidelity steady-state aerodynamic shape optimization to determine its optimum configuration for different flight conditions,including climb,cruise,...The seamless trailing edge morphing flap is investigated using a high-fidelity steady-state aerodynamic shape optimization to determine its optimum configuration for different flight conditions,including climb,cruise,and gliding descent.A comparative study is also conducted between a wing equipped with morphing flap and a wing with conventional hinged flap.The optimization is performed by specifying a certain objective function and the flight performance goal for each flight condition.Increasing the climb rate,extending the flight range and endurance in cruise,and decreasing the descend rate,are the flight performance goals covered in this study.Various optimum configurations were found for the morphing wing by determining the optimum morphing flap deflection for each flight condition,based on its objective function,each of which performed better than that of the baseline wing.It was shown that by using optimum configuration for the morphing wing in climb condition,the required power could be reduced by up to 3.8%and climb rate increases by 6.13%.The comparative study also revealed that the morphing wing enhances aerodynamic efficiency by up to 17.8%and extends the laminar flow.Finally,the optimum configuration for the gliding descent brought about a 43%reduction in the descent rate.展开更多
Recently, various studies of micro air vehicle （MAV） and unmanned air vehicle （UAV） have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing...Recently, various studies of micro air vehicle （MAV） and unmanned air vehicle （UAV） have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing in low Reynold＇s number region to develop an applicative these air vehicle. As an attractive tool in delta wing, leading edge flap （LEF） is employed to directly modify the strength and structure of vortices originating from the separation point along the leading edge. Various configurations of LEF such as drooping apex flap and upward deflected flap are used in combination to enhance the aerodynamic characteristics in the delta wing. The fluid force measurement by six component toad ceil and particle image velocimetry （PIV） analysis are performed as the experimental method. The relations between the aerodynamic superiority and the vortex behavior around the models are demonstrated.展开更多
AIM：To assess and compare the morphology of corneal flaps created by the Wavelight FS200 and Intralase FS60 femtosecond lasers in laser in situ keratomileusis（LASIK）.METHODS：Four hundred eyes of 200 patients were ...AIM：To assess and compare the morphology of corneal flaps created by the Wavelight FS200 and Intralase FS60 femtosecond lasers in laser in situ keratomileusis（LASIK）.METHODS：Four hundred eyes of 200 patients were enrolled in this study and divided into Wavelight FS200 groups（200 eyes） and Intralase FS60 groups（200 eyes）.Fourier-domain optical coherence tomography（RTVue OCT） was used to measure the corneal flap thickness of 36 specified measurements on each flap one week after surgery.Results were used to analyze the regularity,uniformity and accuracy of the two types of LASIK flaps.RESULTS：The mean thickness of corneal flap and central flap was 105.71±4.72 μm and 105.39±4.50 μm in Wavelight FS200 group and 109.78±11.42 μm and 109.15±11.59 μm in Intralase FS60 group,respectively.The flaps made with the Wavelight FS200 femtosecond laser were thinner than those created by the Intralase FS60 femtosecond laser（P=0.000）.Corneal flaps in the 2 groups were uniform and regular,showing an almost planar configuration.But the Wavelight FS200 group has more predictability and uniformity of flap creation.The mean deviation between achieved and attempted flap thickness was smaller in the Wavelight FS200 group than that in the Intralase FS60 group,which were 5.18±3.71 μm and 8.68±7.42 μm respectively.The deviation of more than 20 μm was 0.2% measurements in Wavelight FS200 group and 8.29% measurements in Intralase FS60 group.CONCLUSION：The morphologies of flaps created by Wavelight FS200 are more uniform and thinner than those created by Intralase FS60.展开更多
The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion（IR） and its mechanism. Forty-eight adult male SD rats were randomly divided into 3 groups：...The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion（IR） and its mechanism. Forty-eight adult male SD rats were randomly divided into 3 groups： control group（n=16）, IR group（n=16）, and edaravone-treated IR group（n=16）. An island flap at left lower abdomen（6.0 cm×3.0 cm in size）, fed by the superficial epigastric artery and vein, was created in each rat of all the three groups. The arterial blood flow of flaps in IR group and edaravone-treated IR group was blocked for 10 h, and then the blood perfusion was restored. From 15 min before reperfusion, rats in the edaravone-treated IR group were intraperitoneally injected with edaravone（10 mg/kg）, once every 12 h, for 3 days. Rats in the IR group and control group were intraperitoneally injected with saline, with the same method and frequency as the rats in the edaravone-treated IR group. In IR group and edaravone-treated IR group, samples of flaps were harvested after reperfusion of the flaps for 24 h. In the control group, samples of flaps were harvested 34 h after creation of the flaps. The content of malondialdehyde（MDA） and activity of superoxide dismutase（SOD） were determined, and changes in organizational structure and infiltration of inflammatory cells were observed by hematoxylin-eosin（HE） staining, apoptotic cells of vascular wall were marked by terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling（TUNEL） assay, and the apoptotic rate of cells in vascular wall was calculated. The ultrastructural changes of vascular endothelial cells were observed by transmission electron microscopy（TEM）. Seven days after the operation, we calculated the flap viability of each group, and marked vessels of flaps by immunohistochemical staining for calculating the average number of subcutaneous vessels. The results showed that the content of MDA, the number of multicore inflammatory cells and apoptotic rate of cells in vascular wall in the edaravone-treated IR group were significantly lower than those in the IR group. The activity of SOD, flap viability and average number of subcutaneous vessels in the edaravone-treated IR group were significantly higher than those in the IR group. All the differences were statistically significant. The ultrastructure injury of vascular endothelial cells in the edaravone-treated IR group was slighter than that in IR group. It was concluded that edaravone can significantly enhance IR flap viability and protect flap vessels, which is related to scavenging oxygen free radicals, reducing the consumption of SOD, reducing the extent of lipid peroxidation and inflammation, and protecting functional structure of vessels in the early stages of reperfusion.展开更多
基金Supported by Research Incubation Fund of Xi’an People’s Hospital(Xi’an Fourth Hospital)(No.FZ-58).
文摘AIM:To evaluate the surgical outcomes of the perfluorocarbon liquid(PFCL)-assisted inverted multilayer internal limiting membrane(ILM)flaps covering technique in macular hole retinal detachment(MHRD)in high myopia with axial length(AL)≥30 mm.METHODS:In this retrospective,interventional,consecutive comparative study,44 MHRD eyes were divided into two groups:the PFCL-assisted inverted multilayer ILM flaps covering technique group(Group 1,21 eyes)and the ILM peeling group(Group 2,23 eyes).The follow-up period was>12mo.Postoperative outcomes,including retinal reattachment,macular hole(MH)closure,and bestcorrected visual acuity(BCVA),were assessed.Statistical analysis using the Mann–Whitney U test and Fisher’s exact test was conducted to compare differences between groups.RESULTS:There were no statistically significant differences in baseline preoperative clinical characteristics,including age,sex,AL,diopters,duration of symptom,lens status,posterior staphyloma presence and extent of RD.Retinal reattachment rates were higher in Group 1(90.5%)than in Group 2(82.6%),without statistical significance(P=0.667).MH closure rates were significantly higher in Group 1(85.7%)than in Group 2(17.4%;P<0.001).The Group-1 BCVA(logMAR)improved significantly from 2.13±0.91 preoperatively to 1.21±0.66 postoperatively(P=0.026).The Group 2 BCVA improved significantly from 1.91±0.53 preoperatively to 1.19±0.41 postoperatively(P=0.032).However,there were no significant differences in visual-acuity improvement between groups(P=0.460).CONCLUSION:This technique offers a more effective approach for improving MH closure rates and postoperative visual function in MHRD with AL≥30 mm in high myopia.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.92371201,52192633,11872293,and 92152301)the Natural Science Basic Research Program of Shaanxi(Grant Nos.2024JC-YBQN-0008,and 2022JC-03)+1 种基金Shaanxi Key Research and Development Program(Grant No.2022ZDLGY02-07)the Joint Natural Science Foundation of China with Guangdong Province for TianHe-II Supercomputer Resources,and the Research Start-up Foundation of Xi’an University of Science and Technology for the High-Level Talent.
文摘The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel aircraft.In this study,a new way of nonlinear flow control by interaction between two flexible flaps is proposed,and their flow control mechanism is studied employing the self-constructed immersed boundary-lattice Boltzmann-finite element method(IB-LB-FEM).The effects of the difference in material properties and flap length between the two flexible flaps on the nonlinear flow control of the airfoil are discussed.It is suggested that the relationship between the deformation of the two flexible flaps and the evolution of the vortex under the fluid-structure interaction(FSI).It is shown that the upstream flexible flap plays a key role in the flow control of the two flexible flaps.The FSI effect of the upstream flexible flap will change the unsteady flow behind it and affect the deformation of the downstream flexible flap.Two flexible flaps with different material properties and different lengths will change their own FSI characteristics by the induced vortex,effectively suppressing the flow separation on the airfoil’s upper surface.The interaction of two flexible flaps plays an extremely important role in improving the autonomy and adjustability of flow control.The numerical results will provide a theoretical basis and technical guidance for the development and application of a new flap passive control technology.
基金Supported by Natural Science Fundation of China(NSFC),No.81271993Shanghai Municipal Health and Family Planning Commission,No.201440352
文摘Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to harvest and sacrifice the deep major artery. These flaps are supplied by a perforating artery issued from the deep peroneal artery or the posterior tibial artery, and the chainlinked adipofascial neurovascular axis around the sural/saphenous nerve. It is a versatile and reliable technique for soft-tissue reconstruction of the heel and ankle region with 180-degrees rotation. In this paper, we present its developing history, vascular basis, surgical techniques including flap design and elevation, flap variations in pedicle and component, surgical indications, and illustrative case reports with different perforating vessels as pivot points for foot and ankle coverage.
文摘BACKGROUND： Major complications after pancreaticoduo- denectomy are usually caused by a leaking pancreaticojejunal anastomosis. Omental flaps around various anastomoses were used to prevent the formation of fistula.
基金Beijing Jishuitan Hospital Nova Program Funding[XKXX201617]。
文摘Objective The objective of this report was to demonstrate the clinical application of free flow-through anterolateral thigh flaps for the treatment of high-tension electrical wrist burns.Methods We collected the data of 8 patients with high-tension electrical wrist burns admitted to Beijing Jishuitan Hospital from January 2014 to December 2018.The clinical and pathological data were extracted from electronic hospital medical records.We obtained follow-up information through clinic visits.Results The injury sites for all 8 patients were the wrists,specifically 5 right and 3 left wrists,all of which were on the flexor side.Five patients had ulnar artery embolism necrosis and patency,with injury to the radial artery.Two patients had ulnar and radial arterial embolization and necrosis.The last patient had ulnar arterial embolization and necrosis with a normal radial artery.After debridement,the wound area ranged from 12 cm×9 cm to 25 cm×16 cm.The diagnoses for the eight patients were type II to type III high-tension electrical wrist burns.Free flow-through anterolateral thigh flaps(combined with great saphenous vein transplantation if necessary)were used to repair the wounds.The prognosis for all patients was good after six months to one year of follow-up.Conclusion Treating wrist types II and III high-tension electrical burns is still challenging in clinical practice.The use of free flow-through anterolateral thigh flaps(combined with great saphenous vein transplantation if necessary)to repair the wound and to restore the blood supply for the hand at the same time is a good choice for treating severe wrist electrical burns.
文摘There is long-standing debate about sensate versus non-sensate free microvascular flaps among microsurgeons. The principle of connecting not only the vascular supply, but also sensitive nerves, in free tissue transfer is attractive. However, increased operating time and partial spontaneous innervation led to the common decision to restrict microsurgical tissue transfer to the vascular anastomosis and to leave the nerves ＂untreated＂. Nevertheless, in special cases such as breast reconstruction or extremity reconstruction, the question about sensory nerve coaptation of the flaps remains open. We present our experience with free microvascular tissue transfer for breast and extremity reconstruction and compare the data with previous literature and conclude that most free flap surgeries do not benefit from nerve coaptation.
基金The researches described in this paper have been carried out in the framework of the Clean Sky Green Regional Aircraft ITD(Low Noise Configuration Domain)and Airgreen2 projectsThe activities have gratefully received funding respectively from the Cleans Sky and the Clean Sly 2 Joint Undertaking,under the European Union FP7 and H2020 research and innovation programs,Grant Agreements No.CSJU-GAM-GRA-2008-001 and No.807089—REG GAM 2018—H2020-IBA-CS2-GAMS-2017.
文摘Abstract Morphing wing structures are widely considered among the most promising technologies for the improvement of aerodynamic performances in large civil aircraft.The controlled adaptation of the wing shape to external operative conditions naturally enables the maximization of aircraft aerodynamic efficiency,with positive fallouts on the amount of fuel burned and pollutant emissions.The benefits brought by morphing wings at aircraft level are accompanied by the criticalities of the enabling technologies,mainly involving weight penalties,overconsumption of electrical power,and safety issues.The attempt to solve such criticalities passes through the development of novel design approaches,ensuring the consolidation of reliable structural solutions that are adequately mature for certification and in-flight operations.In this work,the development phases of a multimodal camber morphing wing flap,tailored for large civil aircraft applications,are outlined with specific reference to the activities addressed by the author in the framework of the Clean Sky program.The flap is morphed according to target shapes depending on aircraft flight conditions and defined to enhance high-lift performances during takeoff and landing,as well as wing aerodynamic efficiency during cruise.An innovative system based on finger-like robotic ribs driven by electromechanical actuators is proposed as morphing-enabling technology;the maturation process of the device is then traced from the proof of concept to the consolidation of a true-scale demonstrator for pre-flight ground validation tests.A step-by-step approach involving the design and testing of intermediate demonstrators is then carried out to show the compliance of the adaptive system with industrial standards and safety requirements.The technical issues encountered during the development of each intermediate demonstrator are critically analyzed,and justifications are provided for all the adopted engineering solutions.Finally,the layout of the true-scale demonstrator is presented,with emphasis on the architectural strengths,enabling the forthcoming validation in real operative conditions.
文摘Mesenchymal stem cells(MSCs), multipotential cells that reside within the bone marrow, can be induced to differentiate into various cells, such as osteoblasts, adipocytes, chondrocytes, vascular endothelial progenitor cells, and other cell types. MSCs are being widely studied as potential cell therapy agents due to their angiogenic properties, which have been well established by in vitro and in vivo researches. Within this context, MSCs therapy appears to hold substantial promise, particularly in the treatment of conditions involving skin grafts, pedicle flaps, as well as free flaps described in literatures. The purpose of this review is to report the new advances and mechanisms underlying MSCs therapy against skin flaps necrosis.
基金supported from the National Natural Science Foundation of China (No. 11472129)the Science and Technology on Rotorcraft Aeromechanics Laboratory Foundation of China (No. 6142220050416220002)+2 种基金the Foundation of Graduate Innovation Center in NUAA of China. (No. KFJJ20170102)the Fundamental Research Funds for the Central Universities of Chinaa project funded by the Priority Academic Program Development of Jiangsu Higher Educational Institution of China
文摘Gurney Flaps(GFs) are used for improving the performance of variable speed tail rotors. A validated analytical helicopter model able to predict the main and tail rotor power is utilized. The fixed height GF has substantially small influence on the tail rotor power in hover and low to medium speed forward flight, and can obtain significant power reduction in high speed flight.This ability can be enhanced by decreasing the tail rotor speed. With the deployment of GF, the collective pitch of the tail rotor decreases, and the maximum tail rotor thrust increases. The GF can compensate the reduction of the maximum thrust by the decrease in the tail rotor speed. The GF with a height of 5% of the chord length can almost remedy 50% of the thrust reduction introduced by decreasing 10% of the tail rotor speed. With the increase of GF height, the maximum thrust generated by the tail rotor increases. The GF with larger height can cause the increase in the tail rotor power in hover and low to medium speed flight. The retractable GF can obtain more power savings than the fixed height GF. However, the benefit is substantially small even in high speed flight. Considering the side effects introduced by the active GF, the fixed height GF may be more preferable. The mechanism for the retractable GF to generate more tail rotor thrust is to increase the lift in advancing side due to the higher dynamic pressure.
基金Supported by Jilin Province Science and Techology Development Plan Project(No.20150414032GH)
文摘· AIM: To reconstruct the extensive full-thickness defects of eyelids is a challenge for the plastic surgeon because of their complex anatomy and special functions.This article presents and discusses an improved surgical technique in which the orbicularis oculi myocutaneous flap is rotated through a "subcutaneous tunnel" in conjunction with a palatal mucosal graft employed for lining.·METHODS: Data from 22 eyes with extensive full-thickness eyelid defects from various causes between2009 and 2013 were analyzed in this study. After the different layers of eyelid were separated completely, a temporally based orbicularis oculi myocutaneous flap was designed following fishtail lines and was mobilized,leaving the base of the pedicle intact with a submuscular tissue attachment. The flap was then rotated through a "subcutaneous tunnel" to the defect, and the donor site was closed primarily. Posterior lamellar reconstruction was performed with a mucosal graft harvested from the hard palate.·RESULTS: All the flaps were survived without any healing problems. There was no corneal irritation, flap contraction, or significant donor-site morbidity in the follow-up period. The incision scars were almost invisible.The defects were repaired completely, and the evaluations showed satisfactory function and appearance.·CONCLUSION: This technique is an improved singlestage operation and can be applied to repair large, full-thickness eyelid defects from various causes. With our method, the functional and aesthetic results can be obtained in either the upper or lower eyelids.
文摘·AIM: To provide superior cosmetic results and reduce complications, unlike traditional evisceration coupled with implant insertion technique and its modifications,we have developed a novel and simple technique for anophthalmic patients.·METHODS: All patients who underwent the scleral-muscle flaps procedure in evisceration with the placement of hydroxyapatite implant were included in the study. Main outcome measures were complications such as exposure, infection, chemosis, conjunctival inclusion cysts, granulomas. Meanwhile, implant motility was indirectly measured and the results were collected and analyzed.· RESULTS: A total of twenty-eight patients were enrolled in the study. Eighteen were men(64.29%) and ten were women(35.71%). Ages ranged from 18 to 65y(mean age, 32 years old). Mean follow-up was 12.32mo(range, 9-16mo). All patients received a hydroxyapatite implant. The average diameter of the implant was 19.29 ±1.36 mm(range, 18-22 mm). Minor complications occurred in 3 patients, and a major complication was observed in 1 patient. Mean motility were 11.04 ±1.45 mm horizontally(range, 7-14 mm) and 8.57 ±1.50 mm vertically(range, 5-12 mm).·CONCLUSION: The sclera-muscle flaps technique in evisceration with hydroxyapatite implantation is simple and practical that eases the surgical procedure, enables a proper size hydroxyapatite implantation, distinctively reduces complications and provides superior surgery results, especially the motility of the implant.
基金Supported by the National Natural Science Foundation of China(11172135)the National Basic Research Program of China(″973″Program)(2014CB046200)the Fundamental Research Funds for the Central Universities(NS2012036,NJ20130008)
文摘The effect of Gurney flaps with different heights on the S809 airfoil and NH1500 blade is numerically simulated.The influence of the Gurney flap is analyzed at different wind speeds and the comparison of the aerodynamic performance is given between the blades with and without the Gurney flap.The results demonstrate that a Gurney flap added on the blade can greatly increase the efficiency of the wind turbine especially at high wind speeds.
文摘Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January 2009 and December 2013, 19 patients with DSWI after median sternotomy for cardiac surgery were admitted to our hospital, including 14 males(73.7%) and 5 females(26.3%), aged 55±13(18-78) years. According to the Pairolero classification of infected median sternotomies, 3(15.8%) patients were type II, and the other 16(84.2%) were type III. Surgical procedure consisted of adequate debridement of infected sternum, costal cartilage, granulation, steel wires, suture residues and other foreign substances. Sternal reconstruction used the bilateral pectoralis major or plus rectus abdominis muscle flaps to obliterate dead space. The drainage tubes were placed and connected to a negative pressure generator for adequate drainage. Results There were no intraoperative deaths. In 15 patients(78.9%), bilateral pectoral muscle flaps were mobilized sufficiently to cover and stabilize the defect created by wound debridement. 4 patients(21.0%) needed bilateral pectoral muscle flaps plus rectus abdominis muscle flaps because their pectoralis major muscle flaps could not reach the lowest portion of the wound. 2 patients(10.5%) presented with subcutaneous infection, and 3 patients(15.8%) had hematoma. They recovered following local debridement and medication. 17 patients(89.5%) were examined at follow-up 12 months later, all healed and having stable sternum. No patients showed infection recurrence during the follow-up period over 12 months. Conclusion DSWI following median sternotomy may be effectively managed with adequate debridement of infected tissues and reconstruction with bilateral pectoralis major muscle or plus rectus abdominis muscle flap transposition.
文摘BACKGROUND In daily life and work,there are more and more patients with trauma to the hand,which often results in skin and soft tissue defects.Although there are many repair methods,the function and appearance of the fingers will be adversely affected if the repair is inadequate.CASE SUMMARY In the present report we describe an 18-year-old male patient whose right hand was mangled by a machine.X-ray imaging showed that a right hand bone(middle finger)was absent and the alignment was poor.After hospitalization,he was diagnosed with a severe right hand injury,skin and soft tissue defects,partial finger defects,and a skin degloving injury.He underwent reconstructive surgery with anterolateral thigh and ilioinguinal flaps.After two repair operations,satisfactory results were obtained,including good fracture healing,good skin flap shape,and good wrist joint function.CONCLUSION This case highlights the good effect of anterolateral thigh and ilioinguinal flaps repair technique on severe palm injury.
文摘Objective： To study the possibility of using portions of deepithelialized myocutaneous flaps to the reconstruction of thoracic tracheal defects after resection of a large tumor. Methods： From June 2007 to June 2012, five cases of defects of the thoracic trachea were reconstructed by applying portions of deepithelialized myocutaneous flaps. The patients were 27-61 years old with 4 male cases and 1 female. The cervical trachea ranged in diameter from 4-8.5 cm with circumferences of approximately 1/3-2/5 of the bronchial circumference. Results： M1 five patients with thoracic tracheal defects after resection of a large tumor were cured of portions of deepithelialized myocutaneous flaps, with no tracheal stricture remaining and vomica successfully eliminated. During the first 1 to 3 months after the operation, bronchoscopy showed that the tracheal lumens were smooth, and the visible skin of the musculocutaneous flaps became gray and exhibited a small amount of white discharge. Conclusions： Despite this being a small series and short follow-up, this thoracic tracheal reconstruction with portions of deepithelialized myocutaneous flaps shows encouraging preliminary results and could be an alternative to other methods for the treatment of carefully selected patients with thoracic tracheal defects.
基金the Hydra Technologies team in Mexicothe CREATEUTILI Program for their financial support。
文摘The seamless trailing edge morphing flap is investigated using a high-fidelity steady-state aerodynamic shape optimization to determine its optimum configuration for different flight conditions,including climb,cruise,and gliding descent.A comparative study is also conducted between a wing equipped with morphing flap and a wing with conventional hinged flap.The optimization is performed by specifying a certain objective function and the flight performance goal for each flight condition.Increasing the climb rate,extending the flight range and endurance in cruise,and decreasing the descend rate,are the flight performance goals covered in this study.Various optimum configurations were found for the morphing wing by determining the optimum morphing flap deflection for each flight condition,based on its objective function,each of which performed better than that of the baseline wing.It was shown that by using optimum configuration for the morphing wing in climb condition,the required power could be reduced by up to 3.8%and climb rate increases by 6.13%.The comparative study also revealed that the morphing wing enhances aerodynamic efficiency by up to 17.8%and extends the laminar flow.Finally,the optimum configuration for the gliding descent brought about a 43%reduction in the descent rate.
文摘Recently, various studies of micro air vehicle （MAV） and unmanned air vehicle （UAV） have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing in low Reynold＇s number region to develop an applicative these air vehicle. As an attractive tool in delta wing, leading edge flap （LEF） is employed to directly modify the strength and structure of vortices originating from the separation point along the leading edge. Various configurations of LEF such as drooping apex flap and upward deflected flap are used in combination to enhance the aerodynamic characteristics in the delta wing. The fluid force measurement by six component toad ceil and particle image velocimetry （PIV） analysis are performed as the experimental method. The relations between the aerodynamic superiority and the vortex behavior around the models are demonstrated.
文摘AIM：To assess and compare the morphology of corneal flaps created by the Wavelight FS200 and Intralase FS60 femtosecond lasers in laser in situ keratomileusis（LASIK）.METHODS：Four hundred eyes of 200 patients were enrolled in this study and divided into Wavelight FS200 groups（200 eyes） and Intralase FS60 groups（200 eyes）.Fourier-domain optical coherence tomography（RTVue OCT） was used to measure the corneal flap thickness of 36 specified measurements on each flap one week after surgery.Results were used to analyze the regularity,uniformity and accuracy of the two types of LASIK flaps.RESULTS：The mean thickness of corneal flap and central flap was 105.71±4.72 μm and 105.39±4.50 μm in Wavelight FS200 group and 109.78±11.42 μm and 109.15±11.59 μm in Intralase FS60 group,respectively.The flaps made with the Wavelight FS200 femtosecond laser were thinner than those created by the Intralase FS60 femtosecond laser（P=0.000）.Corneal flaps in the 2 groups were uniform and regular,showing an almost planar configuration.But the Wavelight FS200 group has more predictability and uniformity of flap creation.The mean deviation between achieved and attempted flap thickness was smaller in the Wavelight FS200 group than that in the Intralase FS60 group,which were 5.18±3.71 μm and 8.68±7.42 μm respectively.The deviation of more than 20 μm was 0.2% measurements in Wavelight FS200 group and 8.29% measurements in Intralase FS60 group.CONCLUSION：The morphologies of flaps created by Wavelight FS200 are more uniform and thinner than those created by Intralase FS60.
基金supported by Henan Provincial Key Scientific and Technological Project of China(No.132102310088)
文摘The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion（IR） and its mechanism. Forty-eight adult male SD rats were randomly divided into 3 groups： control group（n=16）, IR group（n=16）, and edaravone-treated IR group（n=16）. An island flap at left lower abdomen（6.0 cm×3.0 cm in size）, fed by the superficial epigastric artery and vein, was created in each rat of all the three groups. The arterial blood flow of flaps in IR group and edaravone-treated IR group was blocked for 10 h, and then the blood perfusion was restored. From 15 min before reperfusion, rats in the edaravone-treated IR group were intraperitoneally injected with edaravone（10 mg/kg）, once every 12 h, for 3 days. Rats in the IR group and control group were intraperitoneally injected with saline, with the same method and frequency as the rats in the edaravone-treated IR group. In IR group and edaravone-treated IR group, samples of flaps were harvested after reperfusion of the flaps for 24 h. In the control group, samples of flaps were harvested 34 h after creation of the flaps. The content of malondialdehyde（MDA） and activity of superoxide dismutase（SOD） were determined, and changes in organizational structure and infiltration of inflammatory cells were observed by hematoxylin-eosin（HE） staining, apoptotic cells of vascular wall were marked by terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling（TUNEL） assay, and the apoptotic rate of cells in vascular wall was calculated. The ultrastructural changes of vascular endothelial cells were observed by transmission electron microscopy（TEM）. Seven days after the operation, we calculated the flap viability of each group, and marked vessels of flaps by immunohistochemical staining for calculating the average number of subcutaneous vessels. The results showed that the content of MDA, the number of multicore inflammatory cells and apoptotic rate of cells in vascular wall in the edaravone-treated IR group were significantly lower than those in the IR group. The activity of SOD, flap viability and average number of subcutaneous vessels in the edaravone-treated IR group were significantly higher than those in the IR group. All the differences were statistically significant. The ultrastructure injury of vascular endothelial cells in the edaravone-treated IR group was slighter than that in IR group. It was concluded that edaravone can significantly enhance IR flap viability and protect flap vessels, which is related to scavenging oxygen free radicals, reducing the consumption of SOD, reducing the extent of lipid peroxidation and inflammation, and protecting functional structure of vessels in the early stages of reperfusion.
